Currently, for some services that have a relatively high transmission delay requirement, such as a video and an online game, servers are separately disposed in different regions, so that user equipment (UE) selects a relatively close server to provide a service. However, for UE with relatively strong mobility, when the UE moves from a serving range of a source server to a serving range of a target server, because an Internet Protocol (IP) address of the UE is not changed, the UE still performs service transmission using the source server that is relatively close to the UE before the movement and does not perform service transmission using the target server that is relatively close to the UE after the movement. To hand over from the source server to the target server to perform service transmission, the UE first needs to detach from a network and then reattach to a network. However, this process causes service interruption, and consequently service continuity is poor.
To enable the UE to hand over from the source server to the target server to perform service transmission on the premise that service continuity is ensured, a handover method is provided in the prior art. When the UE moves from a cell of a source base station to a cell of a target base station, the target base station and the source base station complete an X2 interface-based handover process, so that the UE connects to the source server using the target base station. After the X2 interface-based handover process is completed, the source server synchronizes a user context to the target server, so that the UE can obtain a downlink service data packet from the target server.
However, when user context synchronization is completed, because the IP address of the UE is not changed, a source gateway in the serving range of the source server is still used as an anchor. Consequently, although the downlink service data packet for the UE can be obtained from the target server, transmission is still performed using the source gateway, a transmission path is not optimal, and a service transmission delay is still relatively long.